The present invention relates to a self-balancing poppet in a compressed gas flow. The poppet may be used in a regulator in fuel storage and delivery systems.
Compressed gas can be stored in tanks at high pressures such as 10,000 psi. With such high pressures, the pressure of the gas must be reduced before use. To achieve the necessary pressure reduction, a regulator is typically used. The regulator has a seat and a poppet, and the dynamic motion between the seat and poppet provides the necessary pressure reduction. The poppet moves away from the seat to allow the intended outlet pressure to be reached. Once the outlet pressure is reached, the poppet sits on the seat. The contact surface between the poppet and the seat as the poppet sits on the seat seals the compressed gas from the outlet.
The seal produced by the poppet sitting on the seat is formed during the first release of the compressed gas. The poppet is pressed into the seat, which can be made of metal and non-metallic material, to form the seal surface. For every subsequent release of compressed gas, the poppet must return to the seat at the initially formed position. If the poppet returns to the seat at a different angle or lateral position, then the poppet and the seat do not completely seal the compressed gas from the outlet. The result is a leak.
Aside from its contact with the seat, the poppet is in contact with the body of the regulator. Both the poppet and the body of the regulator can be made of metal. As the poppet repeatedly moves to and from the seat, its metallic periphery rubs against the metallic surface of the regulator's body. Such rubbing creates friction which affects the movement of the poppet. It also wears away the periphery of the poppet. This not only affects the alignment of the poppet with respect to the seat but also shortens the life of the regulator. Moreover, debris is produced from the metal-to-metal contact. Given the high rate of flow, such debris can impact the seat with momentum and carve a leak path, thereby negatively affecting the seal between the poppet and the seat.
A poppet may be attached to a spring which guides the poppet by urging it toward the seat. If the spring is positioned around the periphery of the poppet, the spring will contact the metal surface of the regulator body as the poppet moves to and from the seat. As with the contact between the poppet and regulator body, the contact between the spring and regulator body generates debris. The spring's contact with the poppet can also generate debris. If such debris is not contained, it can impact the seat with momentum and carve a leak path, thereby negatively affecting the seal between the poppet and the seat.
Typically, the spring is placed at the end of the poppet. Having the poppet guided at its end is not advantageous. A small degree of tilt at the end produces a much larger lateral displacement where the poppet sits on the seat. A similar result occurs when the poppet's center of gravity is near its end. If the center of gravity of the poppet is near its end, it will rotate about its end, thereby producing a much larger lateral displacement where the poppet sits on the seat.